Spectroscopy of Positronium Molecules and Bose-Einstein Condensates

正电子分子和玻色-爱因斯坦凝聚体的光谱学

• 批准号: 0900919
• 负责人: Allen Mills
• 金额: $ 61万
• 依托单位: University of California-Riverside
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0900919&HistoricalAwards=false
• 关键词: Spectroscopy; Positronium; Molecules; Bose; Einstein

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Positronium, with the chemical symbol Ps, is a very light form of hydrogen atom consisting only of an electron bound to an anti-electron or positron. Being composed of equal amounts of matter and antimatter, the Ps atom lives for only a fraction of a microsecond before annihilating into gamma rays. Nevertheless, its ephemeral existence is long enough for us to learn important things about metrology, chemistry, and the collective properties of matter. Scientists at the University of California, Riverside (UCR) have recently found that dense collections containing millions of Ps atoms can make di-positronium molecules Ps2 in analogy with the well known hydrogen molecules H2. In the period of this award, the team of UCR scientists and their students will measure the properties of the newly discovered molecules and will assemble and study the first Bose-Einstein condensates formed from a dense gas of Ps atoms. These topics are of compelling interest because they represent new species of antimatter that should exhibit fascinating quantum properties that will be measured via laser spectroscopy. The light mass of positronium means that Bose-Einstein condensation can occur at near room temperature compared to the usual extremely low temperatures of ordinary matter atom traps. Because the positronium atom is fully described in terms of pure quantum electrodynamics theory, precision measurements on the positronium energy levels in the Bose-Einstein condensed state can be directly related to the fundamental constants.In the long term, positron source developments associated with this work will have direct benefits to industry for materials characterization, to medicine for developments in positron emission tomography (PET), and possibly to defense. Achieving a Bose-Einstein condensate of positronium is one of the prerequisites for making an annihilation gamma ray laser which could have significant technological and military applications that would promote the security of the United States, particularly if energies greater than 1 MJ eventually become feasible. The experiments are opening up interdisciplinary aspects of the research, leading to partnering with a variety of institutions and enhancing the educational program at UCR. The fabrication of elaborate microstructures for containing Ps atoms requires applications of silicon technologies such as electron beam lithography. Precision measurements require collaborations with The Time and Frequency Division at the National Institute of Standards and Technology. Further developments of positron technologies are being done in collaboration with scientists from a small business, First Point Scientific Inc., providing a chance for students to learn about the small business side of scientific research. The project will address the problem of attracting underrepresented minorities and women to science using the intriguing concept of antimatter to help attract students from a wide background to the pipeline of scientific inquiry. The research will be published in high impact journals via the web to insure the wide dissemination of the results and its availability to a large audience.

该奖项是根据2009年的《美国回收与再投资法》（公法111-5）的资助。Positronium具有化学符号PS，是一种非常轻的氢原子形式，仅由与反电子或​​positron结合的电子组成。 PS原子由物质和反物质组成，仅在微秒灭入伽玛射线之前仅以微秒为单位生存。然而，它的短暂存在足以让我们学习有关计量学，化学和物质集体特性的重要知识。加利福尼亚大学河滨分校（UCR）的科学家最近发现，包含数百万个PS原子的密集收集可以与众所周知的氢分子H2类似于二峰分子PS2。在此奖项期间，UCR科学家及其学生团队将测量新发现的分子的特性，并将组装和研究由PS原子密集的气体形成的第一个Bose-Einstein冷凝物。这些主题引人注目，因为它们代表了新的反物质物种，该物种应表现出引人入胜的量子特性，这些特性将通过激光光谱法测量。阳性质量的轻质质量意味着与普通物质原子陷阱的通常极低的温度相比，玻色网凝结可能在室温接近。由于正电子原子是根据纯量子电动力学理论的充分描述的，因此对Bose-Einstein凝结状态的正电子能量水平的精确度量可以与基本常数直接相关。在长期来看，与该工作相关的正电子来源开发对材料特征的材料特征的直接效益将对POTITERS INTITRONS INTICTRONS INSICTION（PET）进行质疑（Petrons potsrons sissionssions and sossickron）（Petrons），并具有petrons sissistion（Petron）的作用（）。实现正百发的玻色网凝结物是制造an灭伽玛射线激光器的先决条件之一，该伽玛射线激光器可能具有重要的技术和军事应用，这将促进美国的安全，尤其是如果大于1 MJ的能量最终变得可行。这些实验正在开辟研究的跨学科方面，从而与各种机构合作，并在UCR上加强教育计划。含有PS原子的精心制作的微观结构需要应用硅技术，例如电子束光刻。精确测量需要与国家标准技术研究所的时间和频分部进行合作。正电子技术的进一步发展是与小型企业First Point Scientific Inc.的科学家合作进行的，为学生提供了了解科学研究的小型企业方面的机会。该项目将解决一个问题，即使用有趣的反物质概念来吸引代表性不足的少数民族和妇女进入科学，以帮助吸引从广泛背景的科学探究渠道的学生。该研究将通过网络发表在高影响期刊上，以确保结果的广泛传播及其对大众受众的可用性。